diff --git a/block/block-backend.c b/block/block-backend.c
index 5fb3890bab6d..3203b2569577 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1563,7 +1563,7 @@ BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
                         flags | BDRV_REQ_ZERO_WRITE, cb, opaque);
 }
 
-int blk_pread(BlockBackend *blk, int64_t offset, int bytes, void *buf,
+int blk_pread(BlockBackend *blk, int64_t offset, int64_t bytes, void *buf,
               BdrvRequestFlags flags)
 {
     int ret;
@@ -1577,8 +1577,8 @@ int blk_pread(BlockBackend *blk, int64_t offset, int bytes, void *buf,
     return ret;
 }
 
-int blk_pwrite(BlockBackend *blk, int64_t offset, int bytes, const void *buf,
-               BdrvRequestFlags flags)
+int blk_pwrite(BlockBackend *blk, int64_t offset, int64_t bytes,
+               const void *buf, BdrvRequestFlags flags)
 {
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
     IO_OR_GS_CODE();
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
index e2e7ab9e6c01..8bf1296105b3 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -101,10 +101,10 @@ int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
  * the "I/O or GS" API.
  */
 
-int blk_pread(BlockBackend *blk, int64_t offset, int bytes, void *buf,
+int blk_pread(BlockBackend *blk, int64_t offset, int64_t bytes, void *buf,
               BdrvRequestFlags flags);
-int blk_pwrite(BlockBackend *blk, int64_t offset, int bytes, const void *buf,
-               BdrvRequestFlags flags);
+int blk_pwrite(BlockBackend *blk, int64_t offset, int64_t bytes,
+               const void *buf, BdrvRequestFlags flags);
 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
                                int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);